春风油田排66块火成岩储层成因模式分析

排66块石炭系火成岩岩性复杂、储集空间类型多样,有利储层发育规律和分布模式认识不清。为实现油藏有效动用,有必要开展储层成因模式的分析,指导油藏开发。基于岩芯、成像和分析化验资料,利用地质统计学方法确定本区的主要岩石类型为安山岩和凝灰岩,主要的储集空间包括溶蚀孔洞、裂缝,原生孔隙发育程度弱,无法独自形成有效储层。通过对3种储层类型分布规律的研究,建立了本区火成岩储层的成因模式：岩性控制了储层的范围、构造运动是裂缝形成的直接原因、成岩作用塑造现今储层的发育规律,缝洞储层一般沿断层带分布,在纵向上受控于有利成岩相带。     

Studies on satellite and ground-based measurements of aerosols over urban environment

EP/TOMS satellite-derived aerosol index (AI) data have been analyzed over typical tropical urban environment corresponding to Hyderabad, India to study seasonal and annual distribution of UV-absorbing aerosols. Observations reveal that UV-absorbing aerosol loading is highly seasonal. During the years 1987, 1991 and 1992 high concentration of UV-absorbing aerosols into the atmosphere over Hyderabad region has been observed. UV-absorbing aerosols are high during summer period. Ground-based measurements of aerosol optical depth (AOD) and satellite-derived AI showed good correlation with AOD at .     

贵州松桃地区早震旦世大塘坡期沉积环境及锰矿成因

该区大塘坡期为泻湖-潮坪环境,对锰矿床的形成具有明显的控制作用。作者还以矿床地质特征为依据,结合化学成分测定、同位素资料、稀土元素分析、阴极发光技术和数理统计分析,提出该矿床锰质来源于海底火山喷发的观点。     

汤加火山的地震学研究

俯冲带的地震监测仍然是一个挑战,特别是对于人口稠密地区。2022年1月汤加的洪阿汤加—洪阿哈阿帕伊火山的喷发以及引发的地震凸显了这一需求的急迫性。综合汤加地震学观测,推测汤加部分火山近期仍有小规模喷发风险。选取2009—2010年覆盖汤加的海底地震仪台阵数据,应用机器学习算法进行数据处理,得到汤加火山岛链附近高分辨率的地震目录。     

徐家围子断陷火山机构类型及其地质指示意义

庆深气田的勘探开发实践表明,火山岩气藏呈现出以孤立火山机构控藏的特征.火山机构的横向分布规律及其预测成为火山岩勘探开发的难点.在徐家围子断陷营城组开展了精细的火山岩地层结构对比研究,发现火山喷发受深大断裂控制,具有横向迁移和纵向多旋回叠置的特征.根据火山机构的地球物理响应特征及其地质指示意义,将火山机构分为层状火山、平状火山、歪斜火山、熔岩穹窿、破火山五大类.层状火山和歪斜火山指示了火山沿构造断裂带大规模的爆发与喷溢,形成了大面积广泛发育的火山熔岩和火山碎屑岩互层的地层,构成营城组火山岩地层的主体.火山机构错叠连片,火山岩储层发育.平状火山指示了火山强烈的风化剥蚀作用,风化壳储层发育,可形成高产的火山岩气藏.破火山口和熔岩穹窿指示了火山活动的局部性,破火山是局部火山能量瞬间快速的释放,形成大量的火山碎屑堆积,以致密储层发育为特征;熔岩穹窿是火山作用后期的产物,储层发育,但规模较小.     

Three-dimensional isothermal lava flows over a non-axisymmetric conical surface

Within the thin-layer approximation for a highly-viscous heavy incompressible fluid, a hydrodynamicmodel of a 3D isothermal lava flow over a non-axisymmetric conical surface is constructed. Using analytical methods, a self-similar solution for the law of leading-edge propagation is obtained in the case of a flow from a non-axisymmetric source located at the apex of a conical surface with smoothly varying properties. In the case of a flow over a substantially non-axisymmetric surface, it is shown that there exists a self-similar solution for the free-surface shape and the law of leading-edge motion. This solution is studied numerically for particular examples of the substrate surface and the source. In the general case of a non-self-similar flow over a substantially non-axisymmetric conical surface, a local analytical solution is obtained for the free-surface shape and the velocity field near the leading flow front.     

Fire eruption through intensity and spread rate interaction mediated by flow attachment

Conditions under which a fire has a stable steady spread rate or under which it is able to spread eruptively up a slope or in confined topography are of considerable interest from a practical and safety point of view. The physical interactions that give rise to either form of behaviour are investigated by way of a mathematical model, in which different expressions for the rate of feedback from intensity into spread-rate are found to identify a threshold between eruptive and stable spread of a line fire. In turn, changes in the fireline intensity in any unsteady evolution are mainly determined by the history of the spread-rate over a burnout time (in effect, by changes in flame depth). Under stable conditions, any initial spread-rate evolves towards the steady spread rate on a time-scale of the order of the burnout time. But above the threshold, eruptive fire-growth sets in; the spread-rate and intensity both grow indefinitely.

It is argued that a change in the nature of the flow field around a line fire engenders the change from one form of behaviour to another. If the air flow separates at the flame, so that air is drawn away from the ground and vegetation surface, then the model provides strong reasons to expect that the steady spread rate is stable. On the other hand, laboratory experiments and a controlled field burn confirm that eruptive behaviour is more likely to be associated with flow attachment.

As a result, if the air immediately ahead of a fire that is spreading uphill, flows up the slope away from the fire then conditions arise for a potentially very dangerous acceleration in the spread-rate of the fire, along with a corresponding growth in its intensity. As is shown by the experiments, this form of air-flow can be generated by the fire itself without any change in external conditions such as ambient wind.     

Orthogonal regression: a teaching perspective

A well-known approach to linear least squares regression is that which involves minimizing the sum of squared orthogonal projections of data points onto the best fit line. This form of regression is known as orthogonal regression, and the linear model that it yields is known as the major axis. A similar method, reduced major axis regression, is predicated on minimizing the total sum of triangular areas formed between data points and the best fit line. Either of these methods is appropriately applied when both x and y are measured, a typical case in the natural sciences. In comparison to classical linear regression, equation derivation for the slope of the major axis and reduced major axis lines is a nontrivial process. For this reason, derivations are presented herein drawing from previous literature with as few steps as possible to enable an easily accessible understanding. Application to eruption data for Old Faithful geyser, Yellowstone National Park, Wyoming and Montana, USA enables a teaching opportunity for choice of model.     

古龙断陷营城组一段火山岩特征与火山喷发模式

 利用钻、测井及地震等资料和技术,对松辽盆地古龙断陷营城组一段火山岩特征及火山喷发模式进行研究。结果表明,研究区发现有火山熔岩、火山碎屑熔岩、火山碎屑岩和沉火山碎屑岩4类火山岩石类型,主要发育爆发相、喷溢相和火山沉积相3种火山岩相。平面上,爆发相火山岩主要发育在研究区北部,沿各级控陷断裂呈串珠状分布;喷溢相火山岩沿断裂向构造低部位运移,在研究区大部分地区都有分布;火山沉积相主要分布在断陷的构造低部位。根据研究结果建立了研究区火山岩沿各级控陷断裂喷发的裂隙-中心式喷发模式。